Add rough container type and runc runtime

Signed-off-by: Michael Crosby <crosbymichael@gmail.com>

runc/runc.go

@@ -0,0 +1,117 @@
+package runc
+
+import (
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"strconv"
+	"syscall"
+
+	"github.com/docker/containerkit"
+)
+
+func New(root, log string) (*Runc, error) {
+	if err := os.MkdirAll(root, 0711); err != nil {
+		return nil, err
+	}
+	return &Runc{
+		root: root,
+		log:  log,
+	}, nil
+}
+
+type Runc struct {
+	root string
+	log  string
+}
+
+func (r *Runc) Create(c *containerkit.Container) (containerkit.ProcessDelegate, error) {
+	pidFile := fmt.Sprintf("%s/%s.pid", filepath.Join(r.root, c.ID()), "init")
+	cmd := r.command("create", "--pid-file", pidFile, "--bundle", c.Path(), c.ID())
+	cmd.Stdin, cmd.Stdout, cmd.Stderr = c.Stdin, c.Stdout, c.Stderr
+	if err := cmd.Run(); err != nil {
+		return nil, err
+	}
+	data, err := ioutil.ReadFile(pidFile)
+	if err != nil {
+		return nil, err
+	}
+	i, err := strconv.Atoi(string(data))
+	if err != nil {
+		return nil, err
+	}
+	return newProcess(i)
+}
+
+func (r *Runc) Start(c *containerkit.Container) error {
+	return r.command("start", c.ID()).Run()
+}
+
+func (r *Runc) Delete(c *containerkit.Container) error {
+	return r.command("delete", c.ID()).Run()
+}
+
+func (r *Runc) Exec(c *containerkit.Container, p *containerkit.Process) (containerkit.ProcessDelegate, error) {
+	f, err := ioutil.TempFile(filepath.Join(r.root, c.ID()), "process")
+	if err != nil {
+		return nil, err
+	}
+	path := f.Name()
+	pidFile := fmt.Sprintf("%s/%s.pid", filepath.Join(r.root, c.ID()), filepath.Base(path))
+	err = json.NewEncoder(f).Encode(p.Spec())
+	f.Close()
+	if err != nil {
+		return nil, err
+	}
+	cmd := r.command("exec", "--process", path, "--pid-file", pidFile, c.ID())
+	cmd.Stdin, cmd.Stdout, cmd.Stderr = p.Stdin, p.Stdout, p.Stderr
+	data, err := ioutil.ReadFile(pidFile)
+	if err != nil {
+		return nil, err
+	}
+	i, err := strconv.Atoi(string(data))
+	if err != nil {
+		return nil, err
+	}
+	return newProcess(i)
+}
+
+func (r *Runc) command(args ...string) *exec.Cmd {
+	return exec.Command("runc", append([]string{
+		"--root", r.root,
+		"--log", r.log,
+	}, args...)...)
+}
+
+func newProcess(pid int) (*process, error) {
+	proc, err := os.FindProcess(pid)
+	if err != nil {
+		return nil, err
+	}
+	return &process{
+		proc: proc,
+	}, nil
+}
+
+type process struct {
+	proc *os.Process
+}
+
+func (p *process) Pid() int {
+	return p.proc.Pid
+}
+
+func (p *process) Wait() (uint32, error) {
+	state, err := p.proc.Wait()
+	if err != nil {
+		return 0, nil
+	}
+	return uint32(state.Sys().(syscall.WaitStatus).ExitStatus()), nil
+}
+
+func (p *process) Signal(s os.Signal) error {
+	return p.proc.Signal(s)
+}